org.jetbrains.annotations

Annotation Type BlockingExecutor

@Documented
 @Retention(value=CLASS)
 @Target(value={TYPE,TYPE_USE})
public @interface BlockingExecutor

Indicates that the annotated executor (CoroutineContext, Scheduler) allows blocking methods execution.

If a given executor does not allow blocking calls, NonBlockingExecutor should be used.

Example 1 (Kotlin coroutines):

  class BlockingExampleService {
      val dispatcher: @BlockingExecutor CoroutineContext
          get() { ... }

      suspend fun foo() {
          val result = withContext(dispatcher) {
              blockingBuzz() // no IDE warning
          }
      }

      @Blocking fun blockingBuzz() { ... }
  }
 

Example 2 (Java with Reactor framework):

 class BlockingExampleService {
     private static final @BlockingExecutor Scheduler blockingScheduler =
             Schedulers.newBoundedElastic(4, 10, "executor");

     public Flux<String> foo(Flux<String> urls) {
         return urls.publishOn(blockingScheduler)
                 .map(url -> blockingBuzz(url));  // no IDE warning
     }

     @Blocking
     private String blockingBuzz(String url) { ... }
 }
 

See Also:

Blocking, NonBlocking